Category: PVC

Gone are the times that roofing systems were only a simple part of a building. Roofing systems are increasingly trending toward saving money and energy, and providing other environmental benefits. And this trend should continue.

White is the New Green

While in London in 2009, President Obama’s Energy Secretary Steven Chu, told his former colleagues at the Lawrence Berkeley National Laboratory that painting roofs white to reflect sunlight can make a huge difference to global warming.

Energy Secretary Steven Chu

“There’s a friend of mine, a colleague of mine, Art Rosenfeld, who’s pushing very hard for a geo-engineering we all believe will be completely benign, and that’s when you have a flat-top roof building, make it white. “Now, you smile, but he’s done a calculation, and if you take all the buildings and make their roofs white and if you make the pavement more of a concrete type of color rather than a black type of color, and you do this uniformly . . . it’s the equivalent of reducing the carbon emissions due to all the cars on the road for 11 years.”

PVC is one of the most widely used plastics in the world. It has been used in the medical industry for over 50 years in flexible containers and tubing. And it has been used in roofing systems since the early 1960s. But what happens when the roof has come to the end of its useful life? Oscoda Plastics, Inc., a sister company to Duro-Last Roofing, Inc., has been recycling PVC, primarily manufacturing scrap from Duro-Last, since 1989 and turning it into PROTECT-ALL Commercial Flooring. PROTECT-ALL is a commercial grade flooring system that is slip resistant, durable, easy to maintain, and provides stain and fire protection.

Watch this short video on how a 20-year-old Duro-Last roof was recycled into PROTECT-ALL flooring and used again, now on the deck sheet folding floor at Duro-Last’s Saginaw production facility.

If you would like additional information on how to recycle your Duro-Last roof, visit this link for additional information.

There is an anti-plastics movement which comes and goes in intensity, and has an agenda seemingly focused on finding products to demonize. PVC is often the target.

Earlier this year, the Duro-Last® roofing system was installed on a large project in the Pacific Northwest. However, the owners of the facility requested that we not promote our involvement with this project, apparently concerned that being associated with a PVC roofing membrane will lessen their environmental standing in the public’s eye.

Which opens the door to an educational opportunity.

With respect to roofing systems, the question we have is: “If not PVC, then what?” That’s where the anti-PVC arguments start to break down.

Believe it or not, many activists think we should go back to thatched roofs. Natural, of course, but safe? We would have an explosion in mold, bacteria, insects, rodents, etc. To prevent or get rid of these problems, we’d have to use poisons or other chemicals and there would be another outcry. Let’s not even talk about fire safety.

Other natural products, those made from clay for example, actually are more environmentally damaging when you look at their impact during the mining process and the amount of energy (fossil fuels) required to bring such heavy products to market.

PVC is among the most recyclable materials in the marketplace – just one of the attributes that make it a “green” product. Duro-Last recycles virtually all of its own manufacturing waste. On job sites, it is safer for contractors to handle than other roofing materials that require VOC adhesives, hot tar (which has a very high carbon content, by the way), etc. Unlike other systems, PVC roofs can be recycled at the end of their service lives and Duro-Last has a program in place to do just that.

Eliminating PVC products in hospitals would require other materials that are more prone to bacteria growth. That’s why PVC has been so widely used in blood bags and hospital mattresses – it’s easiest to keep clean.

A recent report issued by the US Green Building Council’s Technical and Scientific Advisory Committee (TSAC) found (after a five year study) that PVC is as benign as other construction products, and in some cases is the best environmental option. A fair evaluation looks at the whole, long-term picture to determine whether the net result of using the product is positive or negative.

The building owners for the roofing project noted above made the right choice with respect to providing long-term watertight protection for their facility. We are confident they made the right environmental choice as well.

Many are at least somewhat familiar with green design programs such as LEED® and Green Globes. The ENERGY STAR® Roof Products Program and the Cool Roof Ratings Council have been providing lists of qualified or rated products for years now, however, recently there have been some questions about another design guide and what it has to say about cool roofing.

The guides give general recommendations in the Building Envelope sections stating that cool or “solar reflective” roofs help reduce energy usage. They do not offer the specificity of LEED or Green Globes, rather they make general recommendations like “increase roof surface reflectance and emittance.”

They also provide useful charts and climate maps that indicate relative performance of various types of roofing products and areas of the country that may benefit most from cool roofing systems.

The Advanced Energy Design Guides are available as free downloads from www.ashrae.org/aedg. Highly reflective white membranes, such as what’s used in the Duro-Last® Cool Zone® roofing system offer a great opportunity for owners of small buildings to achieve real energy savings.

The bill allows a tax credit for up to 10% of the amount paid by the taxpayer for qualified nonbusiness energy efficiency improvements to a maximum lifetime limit of $500. If more than $500 of these tax credits were already taken between 2006 and 2010, there can be no further credits taken. This is a reduction from the $1,500 credit allowed in the original bill.

The credit applies to principal residential property placed in service between January 1, 2011 and December 31, 2011.

Among the qualifying improvements are windows and doors, metal and asphalt roofing, insulation, HVAC equipment, water heaters, geothermal heat pumps, and solar energy systems. All must be ENERGY STAR® qualified products. Unfortunately, single-ply membranes, such as the Duro-Last® Cool Zone® roofing system still do not qualify for the residential energy efficiency tax credit. However tax policy and incentive programs are constantly being revised. We’ll stay on top of things and report on changes when they occur.

When considering reroofing options for commercial facilities, it’s important to keep in mind that not all “new” roofing materials are compatible with “old” materials. Case in point: PVC membrane roofing products are not compatible with asphalt-based products. Like oil and water, like Superman and Kryptonite, like a tuxedo and brown loafers, it’s best to keep these two materials away from each other.

If you’ve made the decision to replace or re-cover your old asphalt roof with a new PVC membrane, here are some common issues that can affect the quality of your new roofing installation:

Tear-offs of asphalt roofs often create dust that contaminates new membrane. To avoid this problem, consider the wind direction and take steps to ensure that dust blows away from PVC materials. Use a tarp on PVC materials that are placed near the tear-off so that asphalt dust does not get on the new membrane. Develop a work plan to make sure that asphalt-contaminated shoes or boots do not get on the membrane. And complete the entire asphalt tear-off before beginning the PVC installation.

Make sure that proper, compatible sealants are used on the new membrane. Many caulks, sealants, and pitch pocket fillers contain asphalt, and should never be used on PVC.

If your project involves re-covering the built-up roof rather than tearing it off, a suitable separator must be installed between the old asphalt and new PVC roofing systems. Insulation materials such as EPS or EXPS rigid foam (whether fanfold or board – as long as it has an approved facer) and polyiso foam board work well. At a minimum, Duro-Last® requires the use of one of our polyethylene separator sheets, either the Duro-Weave™ or Duro-Blue™ product.

If asphalt does come into contact with the new PVC membrane, clean it immediately, because it will “bleed” into the membrane and become impossible to remove. Never use a solvent to clean asphalt off the membrane. Solvents melt the asphalt and soften the membrane, making the problem worse. Instead, use cleaners like DeWitt’s Remove-It Citrus Spray Cleaner, Simple Green®, or a non-solvent based whitewall tire cleaner.

Follow these few simple steps on your PVC roofing project to get a secure, watertight installation that even Superman would have problems pulling apart.

Be careful what you read! Are PTOs a new competitor in the roofing market? No, it’s an acronym with some misplaced letters from the title of a poorly written magazine article. So much marketing misinformation gets presented as fact that it’s a wonder anyone can make an informed roofing decision. Following is some information that may help in assessing the credibility of statements made about roofing.

PVC roofing is made from two basic components: fossil fuel and salt. Fossil fuel is converted to ethylene and rock salt goes through electrolysis to retrieve chlorine – one of the most abundant elements on earth. These components are combined to produce the vinyl chloride monomer which is used with other components to create PVC membrane.

Europe was early to adopt PVC roofing as a single-ply system of choice. Contrary to some claims, PVC roofing is being sold throughout Europe and in fact enjoys by far the largest market share of any of the thermoplastic single-plies.

White PVC membranes are among the most reflective on the market. The Duro-Last Cool Zone® membrane’s Solar Reflectance Index (SRI) of over 110 exceeds LEED requirements for Sustainable Sites Credit 7.2.

Recyclability is also a key element of many green design programs, and unlike other roofing materials, there are well-established programs for recycling PVC roofing membrane, including one offered by Duro-Last.

Because of its chlorine component, PVC is inherently flame resistant, unlike many other roofing products with higher carbon content. This makes fire ratings easier to achieve, and means that PVC roofing in general is less likely to emit toxic gases than other materials in building fires.

PVC membranes are highly flexible and can be custom-prefabricated before reaching the rooftop for installation. This reduces rooftop labor by minimizing jobsite welding by contractors. In addition, seam integrity is more reliable than for stiffer membranes that are made from materials other than PVC.

So, when evaluating systems for your next commercial roofing project, you may want to ask yourself “Why go with the PTO?” Check the facts; don’t be misled by misinformation, and make an informed decision.

Today is Earth Day and for building owners who are interested in “green” construction issues, the fact that old PVC roof membranes can be recycled may help improve your sales opportunities.

Unlike TPO, built-up, modified bitumen, and EPDM roofing systems, recycling programs for PVC roofing products have been in place for many years. The other types of roofing systems are much more likely to end up in a landfill once their rooftop service is complete.

Duro-Last established our “Recycle Your Roof” program for old PVC membranes in 2005. Material that we obtain from torn-off roofs is typically sent to Oscoda Plastics, Inc. in Oscoda, Michigan, which produces commercial flooring and expansion joints.

Details of the program, including our “Recycle Your Roof” request form, are available in Duro-Last Technical Bulletin #133, which can be downloaded here.

Here’s what the Tech Bulletin has to say about preparing the old roof for recycling:

Roofs and roofing materials that are broomed on the top and bottom surfaces may be considered for the Duro-Last Roof Recycling Program.

The top and bottom surface of the Duro-Last material must be free of stones, debris, fasteners, asphalt, coal tar pitch, and any foreign substances that may be attached or adhered to the material.

After brooming, cut the material free from the roof deck along both sides of the fastening tabs and all penetrations. Discard any heavily soiled or contaminated material. All returning material must be cut into 5 ft. x 5 ft. sections (or smaller), neatly stacked on a pallet and banded for shipping. Fastening tabs and fasteners must not be included in the recycle material.

The completed “Recycle Your Roof” form must be faxed or mailed to Duro-Last one week prior to the material being shipped.

Tip: Use a hook blade with a long handle to cut along fastening tabs.

The contractor pays for shipping to the closest Duro-Last manufacturing plant.

Okay, so you installed a cool roofing system, but since the building already had so much insulation you haven’t noticed any energy savings. What’s the point?

True. High reflectivity is a key characteristic that helps keep buildings cooler and can reduce energy usage. As much as 40% less cooling energy may be needed for buildings that have highly-reflective roofs. But even if a building is very well insulated, here are some other valuable benefits from cool roofing:

Insulation can be 25%-50% more effective

Studies have shown that extremely high temperatures reduce the effective R-value of the most widely used types of insulation (Leonard & Leonard, 2005). Cooler surfaces help preserve and keep rooftop insulation materials cooler.

HVAC equipment can operate more efficiently

Inlet air temperatures can be 5-15 degrees cooler 30 inches above a cool roofing surface compared to a black surface. Most rooftop HVAC units are designed with efficiency ratings evaluated at 95°F (York International, 2005); rooftop temperatures on a black surface can reach 160°F or higher, meaning that HVAC units will not operate at peak efficiency.

Substrate deterioration may be slowed by as much as 75%

Ultraviolet and infrared radiation and moisture penetration accelerate substrate deterioration. A cool roofing system will reflect this radiation and help protect the substrate (Kirn et. Al., 1994).

Ambient interior temperatures can be up to 20°F cooler than outside

Studies of worker performance with machine operation and high physical activity reveal that productivity drops 10% at 84°F and 38% at 95°F (Schweisheimer, W., 1962). So even if a building is not air conditioned occupants will still notice improved comfort on hot days.

Energy savings analysis has been around for years. There are any number of Internet-based calculators, formulas and procedures for estimating the savings associated with products or actions undertaken to reduce or avoid energy usage. Energy savings is but one component of a much more comprehensive analytical process referred to as life cycle analysis or LCA. But LCA is not nearly so well-defined. Unlike energy savings analysis, which considers a limited number of variables that can be reasonably well defined and quantified, there is no uniform procedure for LCA.

There are some Internet-based calculators for LCA, but they range from being over-simplified to exceedingly complex; from being biased toward individual products or special interests to being overly generic and meaningless. Some approaches to LCA only consider short term direct financial burdens while others consider more indirect or subjective costs both upstream and downstream in the life of a product.

On the other hand, a highly comprehensive environmental-based approach might entail the evaluation of all material and energy inputs and outputs at every stage, from the creation of natural resources through extraction, manufacture, use, and demolition, and disposal of a product. Consider the complexity of the following extreme LCA flow example:

Although this second example seems extreme or absurd, it makes the point that there can be limitless considerations in a comprehensive LCA. The difficulty comes in deciding how far to go and making fair and objective assumptions of all criteria at each stage in the life of the product or system. One of the best things LCA helps accomplish is identification of opportunities for improvement. The important thing to remember in addressing this continuous improvement process is to remember that every action has a reaction, so don’t rob Peter to pay Pa